What is the correct sequence of uterine blood flow?
Nerve supply of stapedius is:
The sternocleidomastoid muscle is examined by
Which of the following statements about the anatomy of the right ventricle is correct?
Which artery passes through the anatomical snuffbox?
Which is the largest nerve that exits the pelvis through the greater sciatic foramen?
Inversion and eversion of foot occurs at which joint
What muscle is attached to the superior nuchal line?
Which of the following structures is not related to the third part of the duodenum?
Which nerve is preserved in dissecting the superficial and deep lobes of the parotid gland?
NEET-PG 2015 - Anatomy NEET-PG Practice Questions and MCQs
Question 61: What is the correct sequence of uterine blood flow?
- A. Uterine A → Radial A → Arcuate A → Spiral A
- B. Uterine A → Spiral A → Radial A → Arcuate A
- C. Uterine A → Arcuate A → Spiral A → Radial A
- D. Uterine A → Arcuate A → Radial A → Spiral A (Correct Answer)
Explanation: ***Uterine A → Arcuate A → Radial A → Spiral A*** - The **uterine artery** is the primary blood supply, branching into several arteries within the myometrium. - **Arcuate arteries** encircle the uterus, giving off perpendicular branches called **radial arteries**, which then give rise to the **spiral arteries** that supply the endometrium [1]. *Uterine A → Radial A → Arcuate A → Spiral A* - This sequence is incorrect because **radial arteries** arise from **arcuate arteries**, not the other way around. - **Arcuate arteries** are larger circumferential vessels that branch into the smaller radial arteries. *Uterine A → Spiral A → Radial A → Arcuate A* - This sequence is highly incorrect as **spiral arteries** are the most distal branches supplying the endometrium, not preceding radial or arcuate arteries [1]. - The flow is from larger to smaller vessels, with **spiral arteries** being the smallest and most terminal. *Uterine A → Arcuate A → Spiral A → Radial A* - This sequence incorrectly places **spiral arteries** before **radial arteries**. - **Radial arteries** are the immediate precursors to **spiral arteries**, providing direct branches to them.
Question 62: Nerve supply of stapedius is:
- A. Facial nerve (7th nerve) (Correct Answer)
- B. Oculomotor nerve (3rd nerve)
- C. Trigeminal nerve (5th nerve)
- D. Glossopharyngeal nerve (9th nerve)
Explanation: ***Facial nerve (7th nerve)*** - The **facial nerve** is responsible for innervating the **stapedius muscle**, which helps to dampen loud sounds by pulling the stapes away from the oval window. - A lesion in the facial nerve can lead to **hyperacusis** due to the paralysis of the stapedius muscle. *Oculomotor nerve (3rd nerve)* - The **oculomotor nerve** primarily controls **eye movements** and **pupil constriction**. - It does not have any direct involvement in the innervation of middle ear muscles. *Trigeminal nerve (5th nerve)* - The **trigeminal nerve** is responsible for **sensation of the face** and innervates the **muscles of mastication**. - It provides motor supply to the **tensor tympani muscle**, not the stapedius. *Glossopharyngeal nerve (9th nerve)* - The **glossopharyngeal nerve** is primarily involved in **taste sensation** from the posterior tongue, **swallowing**, and mediating the **gag reflex**. - It does not innervate any muscles of the middle ear.
Question 63: The sternocleidomastoid muscle is examined by
- A. Shrugging of shoulder
- B. Overhead abduction
- C. Turning the head towards the same side to assess the muscle on that side
- D. Turning the head towards the opposite side to assess the muscle on that side (Correct Answer)
Explanation: ***Turning the head towards the opposite side to assess the muscle on that side*** - The **sternocleidomastoid muscle** unilaterally acts to rotate the head to the **contralateral side**. - To palpate or visually inspect the right sternocleidomastoid, the patient would turn their head to the left, making the right muscle prominent. *Turning the head towards the same side to assess the muscle on that side* - Turning the head towards the same side primarily engages the **ipsilateral deep neck flexors** and **splenius capitis**, not the sternocleidomastoid. - This action would relax the sternocleidomastoid on the side towards which the head is turned, making it difficult to assess. *Shrugging of shoulder* - Shrugging the shoulder is primarily an action of the **trapezius** and **levator scapulae muscles**. - The sternocleidomastoid does not contribute significantly to shoulder elevation. *Overhead abduction* - Overhead abduction of the arm is primarily performed by the **deltoid muscle** and assisted by the **supraspinatus**. - This movement is entirely unrelated to the function of the sternocleidomastoid muscle.
Question 64: Which of the following statements about the anatomy of the right ventricle is correct?
- A. TV & PV Share fibrous continuity
- B. More prominent trabeculation
- C. The crista supraventricularis separates the tricuspid and pulmonary valves, and the apex is trabeculated (Correct Answer)
- D. All of the options
Explanation: The crista supraventricularis separates the tricuspid and pulmonary valves, and the apex is trabeculated - The **crista supraventricularis** (also known as the supraventricular crest) is a prominent muscular ridge that separates the **inflow tract** (tricuspid valve region) from the **outflow tract** (pulmonary valve region) in the right ventricle. - The **apex and trabecular portion** of the right ventricle contains prominent **trabeculae carneae**, which are irregular muscular ridges and columns. - This option is correct as it describes two key anatomical features: the structural separator between valves and the trabeculated apex. *TV & PV Share fibrous continuity* - This statement is **anatomically incorrect** for the right ventricle. - The **tricuspid valve** and **pulmonary valve** do NOT share fibrous continuity; they are separated by the **crista supraventricularis** (muscular ridge). - **Fibrous continuity** (mitral-aortic continuity) is a characteristic feature of the **left heart**, where the anterior mitral leaflet is continuous with the aortic valve, but this does NOT occur in the right ventricle. *More prominent trabeculation* - While this statement is **anatomically true** (the right ventricle has more prominent trabeculation than the left ventricle, which has a smoother wall), this option is **incomplete** when compared to the correct answer. - The question asks for the correct statement about right ventricle anatomy, and option 3 provides a **more comprehensive description** that includes both a unique structural landmark (crista supraventricularis) and the trabeculation feature. - In single-best-answer format, the most complete and specific option is preferred. *All of the options* - This option is incorrect because the statement "TV & PV Share fibrous continuity" is anatomically false. - Since not all options are correct, this cannot be the answer.
Question 65: Which artery passes through the anatomical snuffbox?
- A. Radial artery (Correct Answer)
- B. Brachial artery
- C. Ulnar artery
- D. Interosseus artery
Explanation: ***Radial artery*** - The **radial artery** is palpable within the **anatomical snuffbox**, as it courses over the scaphoid and trapezium bones towards the deep palmar arch. - This location is clinically significant for feeling the pulse and is vulnerable to injury, especially during **scaphoid fractures**. *Brachial artery* - The **brachial artery** is found in the **arm**, typically running in the cubital fossa, well proximal to the anatomical snuffbox. - It bifurcates into the radial and ulnar arteries at the level of the elbow, not within the wrist structures. *Ulnar artery* - The **ulnar artery** typically lies on the **medial side of the forearm** and wrist, contributing to the superficial palmar arch. - It does not pass through the anatomical snuffbox, which is located on the lateral aspect of the wrist. *Interosseus artery* - The **interosseus arteries** (anterior and posterior) run between the radius and ulna in the forearm, supplying muscles and bones. - These arteries are deep within the forearm compartments and do not traverse the superficial anatomical snuffbox at the wrist.
Question 66: Which is the largest nerve that exits the pelvis through the greater sciatic foramen?
- A. Sciatic nerve (Correct Answer)
- B. Superior gluteal artery
- C. Inferior gluteal artery
- D. Piriformis muscle
Explanation: ***Sciatic nerve*** - The **sciatic nerve** is the largest nerve in the human body, formed from the sacral plexus, and it is indeed the largest structure that passes through the **greater sciatic foramen** as it descends into the posterior thigh. - It supplies motor and sensory innervation to the posterior thigh, lower leg, and foot. *Superior gluteal artery* - The superior gluteal artery exits the pelvis through the **greater sciatic foramen** above the piriformis muscle. - While significant, it is an artery and not a nerve, and it is not the largest structure passing through this foramen. *Inferior gluteal artery* - The inferior gluteal artery also exits the pelvis via the **greater sciatic foramen**, inferior to the piriformis muscle. - Like the superior gluteal artery, it is an arterial structure and not a nerve, and it is not the largest structure in the foramen. *Piriformis muscle* - The **piriformis muscle** originates inside the pelvis and passes through the **greater sciatic foramen** to insert on the greater trochanter of the femur. - Although it occupies a significant portion of the foramen, it is a muscle, not a nerve, and the sciatic nerve is the largest nerve exiting this aperture.
Question 67: Inversion and eversion of foot occurs at which joint
- A. Ankle
- B. Subtalar (Correct Answer)
- C. Tarso-metatarsal
- D. None of the options
Explanation: ***Subtalar*** - The **subtalar joint** (talocalcaneal joint) is primarily responsible for **inversion** and **eversion** movements of the foot. - **Inversion** involves tilting the sole of the foot medially (turning inward), while **eversion** involves tilting the sole laterally (turning outward). - This joint allows the foot to **adapt to uneven surfaces** and plays a crucial role in the biomechanics of walking and running. - The subtalar joint is essential for shock absorption and balance during gait. *Ankle* - The **ankle joint** (talocrural joint) is a hinge joint primarily responsible for **dorsiflexion** and **plantarflexion** of the foot. - It allows moving the foot up and down but has minimal contribution to inversion and eversion. *Tarso-metatarsal* - The **tarso-metatarsal joints** (Lisfranc joints) connect the tarsal bones to the metatarsal bones. - These joints contribute primarily to the **stability and arch integrity** of the foot, with minimal movement capacity. - They allow slight gliding movements but not significant inversion or eversion. *None of the options* - This option is incorrect because the **subtalar joint** is indeed the primary joint responsible for inversion and eversion of the foot. - Understanding foot joint biomechanics is essential for diagnosing gait abnormalities, ankle sprains, and foot pathologies.
Question 68: What muscle is attached to the superior nuchal line?
- A. Trapezius muscle (Correct Answer)
- B. Scalenus anterior
- C. Coracobrachialis muscle
- D. Biceps Brachii muscle
Explanation: ***Trapezius muscle*** - The **trapezius muscle** is a large, triangular muscle of the back that extends from the **occipital bone** (including the superior nuchal line) to the lower thoracic vertebrae. - Its **superior fibers** originate from the **medial one-third of the superior nuchal line** and the external occipital protuberance. *Scalenus anterior* - The **scalenus anterior** muscle originates from the **transverse processes of cervical vertebrae**, specifically C3-C6. - It inserts onto the **first rib** and is involved in neck flexion and elevation of the first rib during forced inspiration. *Coracobrachialis muscle* - The **coracobrachialis muscle** originates from the **coracoid process of the scapula**. - It inserts into the **medial surface of the humerus** and is involved in shoulder flexion and adduction. *Biceps Brachii muscle* - The **biceps brachii muscle** has two heads: the short head originates from the **coracoid process**, and the long head originates from the **supraglenoid tubercle of the scapula**. - It inserts onto the **radial tuberosity** and is primarily responsible for elbow flexion and forearm supination.
Question 69: Which of the following structures is not related to the third part of the duodenum?
- A. Superior mesenteric vessels
- B. Right ureter
- C. Head of pancreas
- D. Quadrate lobe of liver (Correct Answer)
Explanation: ***Quadrate lobe of liver*** - The **quadrate lobe of the liver** is located on the visceral surface of the liver, bounded by the gallbladder fossa, ligamentum teres, and porta hepatis. [1] - It is anatomically related to the **first part of the duodenum** and the pylorus, but has **no direct relationship** with the retroperitoneal **third part of the duodenum**, which lies at the L3 vertebral level. [2] - The third part of the duodenum is too inferior and posterior to have any relationship with the quadrate lobe. *Superior mesenteric vessels* - The **superior mesenteric artery** and **vein** cross **anteriorly** to the **third part of the duodenum** as it runs horizontally from right to left. - The duodenum passes between the aorta posteriorly and the superior mesenteric vessels anteriorly, creating a potential site for compression (**superior mesenteric artery syndrome**). *Right ureter* - The **right ureter** is a **posterior relation** of the **third part of the duodenum**, as both structures are retroperitoneal. [2] - The ureter descends on the psoas major muscle, passing behind the third part of the duodenum during its course toward the pelvis. *Head of pancreas* - The **head of pancreas**, specifically the **uncinate process**, lies **superior and posterior** to the **third part of the duodenum**. - The uncinate process hooks around posteriorly to the superior mesenteric vessels and has an intimate relationship with the third part of the duodenum.
Question 70: Which nerve is preserved in dissecting the superficial and deep lobes of the parotid gland?
- A. Glossopharyngeal
- B. Hypoglossal
- C. Lingual
- D. Facial (Correct Answer)
Explanation: ***Correct: Facial*** - The **facial nerve (CN VII)** passes directly through the parotid gland, dividing it into superficial and deep lobes. Dissection of these lobes requires careful identification and preservation of the facial nerve and its branches to avoid paralysis. - Injury to the facial nerve during parotidectomy can lead to various degrees of **facial paralysis**, affecting muscle movements like smiling, eye closure, and forehead wrinkling. *Incorrect: Glossopharyngeal* - The **glossopharyngeal nerve (CN IX)** supplies the carotid sinus and stylopharyngeus muscle and provides secretomotor innervation to the parotid gland via the otic ganglion. - It does not traverse the parotid gland itself, so it is not directly at risk during the dissection of the superficial and deep lobes. *Incorrect: Hypoglossal* - The **hypoglossal nerve (CN XII)** primarily controls the intrinsic and extrinsic muscles of the tongue, responsible for tongue movement. - It is located inferior to the parotid gland and is not in the field of dissection for separating the parotid lobes. *Incorrect: Lingual* - The **lingual nerve**, a branch of the mandibular nerve (CN V3), provides sensation to the **anterior two-thirds of the tongue** and carries parasympathetic fibers for submandibular and sublingual glands. - While it is in the general vicinity of the orofacial region, it does not pass through the parotid gland and is therefore not directly at risk during the dissection of the parotid lobe.